Vehicle monitoring system

ABSTRACT

The systems and methods described herein include monitoring systems and methods that monitor speeds of a motor of a vehicle represented as a pulse signal indicative of a rotational position of the motor. The systems and methods include receive a pulse signal from a speed sensor coupled to a traction motor. The pulse signal is indicative of a rotational position of the traction motor. The systems and methods include analyze the pulse signal to identify per-revolution signal reoccurrences that meet designated criteria, and determine a defect based on the per-revolution signal reoccurrences that are identified. The defect is one or more of a wheel defect, a bearing defect, or a gear defect.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/486,059, filed 17 Apr. 2017, and the entire provisional applicationof which is incorporated herein by reference.

FIELD

Embodiments of the inventive subject matter described herein relate tomonitoring a wheel and/or drivetrain of a vehicle.

BACKGROUND

Rigid wheels of vehicles can develop defects, such as flat spots orsegments along the portion of the wheel that rolls along a surface,shells, spalls, scrapes, dents, gouges, grooves, and the like. Thesetypes of defects can be referred to as wheel visual damage. These typesof damage can be created by wear and tear of the wheel, such as wearingdown of the wheel when the wheel is sliding along the surface. Forexample, the wheels of a rail vehicle can develop flat spots over timedue to wearing down of the wheel by the rails on which the rail vehicletravels. Additionally, bearings in motors that rotate the wheels, axlejournals that couple wheels to axles, gear teeth within the motor,and/or other components of a drivetrain of a vehicle can become worndown and/or damaged over time.

If severe enough, these types of damage can pose a hazard for thevehicle and the rail. For example, the damage can generate vibratoryforces when the wheels rotate along a route, and the forces can damagecomponents of the vehicle. To detect the damage, human operators mayvisually inspect the vehicle when the vehicle is stopped. But, this typeof inspection is subject to human error, can be time consuming, andgenerally can only be performed when the vehicle is not moving. Somesections of tracks for rail vehicles include strain gauges built intothe rails. When a rail vehicle having damage in a wheel travels over thestrain gauges, the strain gauges can detect the increased amount offorce or vibration generated by the damage. But, this type of detectioncan be limited due to the need for the rail vehicle to travel to thelocation of track where the strain gauges are located.

Additionally, bearings in motors that rotate the wheels, axle journalsthat couple wheels to axles, or other components of a drivetrain of avehicle can become worn down and/or damaged over time. If severe enough,these problems can pose a hazard for the vehicle. To detect theseproblems, however, typically operators may inspect the vehicle when thevehicle is stopped. But, this type of inspection also is subject tohuman error, can be time consuming, and generally can only be performedwhen the vehicle is not moving.

BRIEF DESCRIPTION

In an embodiment a system (e.g., monitoring system) is provided. Thesystem includes a speed sensor coupled to a traction motor of an axledrive train of a vehicle. The speed sensor is configured generate apulse signal indicative of a rotational position of the traction motor.The system includes a controller circuit operatively coupled to thespeed sensor. The controller circuit is configured to analyze the pulsesignal to identify per-revolution signal reoccurrences that meetdesignated criteria, and to determine the defect based on theper-revolution signal reoccurrences that are identified. The defect isone or more of a wheel defect, a bearing defect, or a gear defect.

In an embodiment a method (e.g., for monitoring an axle drive train) isprovided. The method includes receiving a pulse signal from a speedsensor coupled to a traction motor. The pulse signal is indicative of arotational position of the traction motor. The method includes analyzingthe pulse signal to identify per-revolution signal reoccurrences thatmeet designated criteria, and determining a defect based on theper-revolution signal reoccurrences that are identified. The defect isone or more of a wheel defect, a bearing defect, or a gear defect.

In an embodiment a system (e.g., monitoring system) is provided. Thesystem includes a controller circuit configured to receive a signal froma speed sensor of a vehicle. The signal representative of rotationalpositions of a motor of the vehicle. The controller circuit isconfigured to analyze the signal to identify per-revolution signalreoccurrences that meet designated criteria, and to determine the defectbased on the per-revolution signal reoccurrences that are identified inone or more of a wheel of the vehicle, a bearing of the vehicle, or agear of the vehicle based on the signal.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference is now made briefly to the accompanying drawings, in which:

FIG. 1 is a schematic illustration of an embodiment of a monitoringsystem of a vehicle;

FIG. 2A-B are schematic illustrations of an embodiment of a portion ofan axle drive train of the vehicle shown in FIG. 1;

FIG. 2C is an expanded illustration of an embodiment of a motor of theaxle drive train shown in FIGS. 2A-B of the vehicle shown in FIG. 1;

FIG. 3 is a flowchart of an embodiment of a method for monitoring anaxle drive train;

FIG. 4 is a graphical illustration of an embodiment of a pulse signal;

FIG. 5A is an illustration of an embodiment of a wheel of the vehiclesubdivided into spatial buckets;

FIG. 5B is an illustration of a flowchart of an embodiment to determinean incremental delta time;

FIG. 6 is a graphical illustration of an embodiment of a spatial array;

FIG. 7 is an illustration of a summing window to form a gear filteredspatial array;

FIG. 8 is a graphical illustration of an embodiment of a gear filteredspatial array;

FIG. 9 is a graphical illustration of an embodiment of the spatialarray, the gear filtered spatial array, and revolutions per minutespatial array;

FIGS. 10-12 are graphical illustrations of an embodiment of a revolutionper minute spatial array;

FIG. 13 is an illustration of an embodiment of accumulating incrementaldelta times into a gear spatial array; and

FIG. 14 is a graphical illustration of an embodiment of a gear spatialarray.

DETAILED DESCRIPTION

One or more embodiments of the inventive subject matter described hereininclude monitoring systems and methods that monitor speeds of a motor ofa vehicle represented as a pulse signal indicative of a rotationalposition of the motor. Based on the pulse signals, the monitoring systemis configured to identify defects to at least one wheel and/or adrivetrain of the vehicle. The defects can include visual wheel damage,which can include damage such as flat portions along the outer perimeterof one or more of the wheels, shells, spalls, scrapes, dents, gouges,grooves, or the like. The defects optionally can include damage to adrivetrain of the vehicle, such as (but not limited to) damaged bearingsof a motor, damaged axle journals, damaged gears, and/or the like.Additionally or alternatively, the defect may include wear, damage, oran undesired manufacturing feature at a given location of a rotationalcomponent, which affects operation of the component on a per-revolutionbasis, but which is not so severe as to preclude the component fromoperating according to its intended purpose during movement of thevehicle.

In one example of damage and/or defects to wheels, the wheels may beinitially or previously round, rigid wheels (e.g., wheels that areforged, cast, or otherwise formed from one or more metals and/or metalalloys) that develop segments along an outer perimeter of the wheels(e.g., along the portion of the wheel that contacts the route beingtraveled upon) that are no longer around. For example, these segmentsmay be considered “flat” or “out-of-round” when one or more portions ofthe perimeter of the wheel have a larger or smaller radius than theaverage radius of the wheel, and/or when the one or more portions of theperimeter of the wheel are flat instead of rounded.

In an embodiment of the monitoring system, damage and/or defects towheels and/or a drivetrain can be identified with one or more onboard oroff-board systems based on a morphology of the pulse signal. Forexample, the monitoring system may determine defects to the wheelsand/or the drivetrain based on peaks of the pulse signal.

Optionally, one or more alerts can be communicated to an onboard and/oroff-board location to notify of the damage and/or defect identified bythe monitoring system. This notification can be used to notify anupcoming repair or maintenance facility to prepare for replacement orrepair of the wheels and/or drivetrain having the damage upon arrival(or relatively soon thereafter) of the vehicle at the facility.Additionally or alternatively, the one or more alerts may automaticallyadjusts the motor (e.g., speed).

FIG. 1 is a schematic illustration of an embodiment of a monitoringsystem 122 of a vehicle 100. The vehicle 100 can represent apropulsion-generating vehicle system that generates tractive effort topropel the vehicle 100 along a route 102. In one example, the vehicle100 may be a rail vehicle such as a locomotive, but alternatively may beanother type of vehicle system. For example, the vehicle 100 may beanother type of off-highway vehicle (e.g., a vehicle that is notdesigned and/or not permitted to travel on public roadways), or may bean automobile. The vehicle 100 includes a plurality of wheels 104 (e.g.,wheels 104 a-d) having outer perimeters 106 that engage the route 102when the vehicle 100 travels along the route 102. With respect to railvehicles, the wheels 104 may be rigid wheels having outer perimeters 106that contact rails of a track. It may be a noted a number and/orarrangement of the wheels 104 can vary from that shown in FIG. 1.

The wheels 104 can be mechanically coupled to an axle drive train havingaxles 108 and a motor 100 (e.g., 110 a-d). For example, the wheels 104are connected to axles 108 that are rotated by motors 110 (e.g., motors110 a-d) to rotate the wheels 104 and cause propulsion of the vehicle100. The motors 110 may be configured to rotate the axles 108 with acompliant coupling or connection. The motors 110 may be traction motors.In connection with FIGS. 2A-C, the motors 110 can be separatelyconnected to individual ones of the axles 108 by gears, pinions, and/orthe like. It may be noted that one or more of the motors 110 may beconnected to two or more of the axles 108.

FIGS. 2A-C are schematic illustrations of an embodiment of a portion ofan axle drive train 200 of the vehicle 100. FIG. 2A illustrates aperipheral view of the axle drive train 200. The axle drive train 200includes the motor 110 and an aperture 206 for the axles 108. Forexample, the axles 108 may be positioned within the aperture 206 andcoupled to the wheel 104. The motor 110 includes an axle gear 202. Theaxle gear 202 is mechanically coupled to the axles 108. The axle gear202 is adjacent to a pinion gear 204, which is operatively coupledtogether via the gear teeth of the axle gear 202 and the pinion gear204. The pinion gear 204 is configured to provide a rotational and/orangular movement to the axle gear 202. For example, the pinion gear 204is mechanically and/or operatively coupled to the motor 110, whichgenerates the rotational and/or angular movement of the pinion gear 204.For example, a motor frame 201 reacts against a bogie frame 207 througha link 205, which may include compliant bushings. Additionally oralternatively, the axles 108 itself is suspended from a bogie frame 207(FIG. 2B) by way of primary suspension springs 203. The combination ofthe springs 203, the link 205, the bogie frame 207, and/or the likeprovide a mechanism for finite transient motor rotor rotation orrevolution relative to the motor stator without the need for wheelrotation and/or translation of the vehicle 100 along the route 102.

FIG. 2B illustrates a peripheral view of the axle drive train 200. Forexample, the axle drive train 200 shown in FIG. 2B includes the axles108 mechanically coupled to the wheels 104 a-d. The axle drive train 200includes bearings 208 and 210. The bearings 208 and 210 may be motorpinion end bearings. For example, the bearings 208 and 210 may beconfigured to constrain movement of the pinion gear 204 along onedirection. The axle drive train 200 may further include bearings 212 and214. The bearings 212 and 214 may be rolling bearings. For example, thebearings 212 and 214 may be configured to constrain movement of theaxles 108, such as within the aperture 206.

FIG. 2C is an expanded illustration of an embodiment of the motor 110 ofthe axle drive train 200 of the vehicle 100. For example, the expandedillustration may illustrate the components, such as the gaskets andcollars 226, contained within a housing 234 of the motor 110. The motor110 includes a terminal box 230 configured to electrically and/oroperably couple the motor 110 to a controller circuit 112. The motor 110may include a pair of bearing caps 220 and bearing housing 224. Thebearing caps 220 and bearing housing 224 are configured to enclose andprotect the bearings 208 and 210. The motor 110 may include a frame head218 coupled to the housing 234 using a connection rings 222. The framehead 218 is configured to support the axles 108 and the speed sensor118. The speed sensor 118 is operably coupled to a speed sensor gear216. For example, the speed sensor 118 is configured to utilize and/ormeasure changes in a position of the speed sensor gear 216 to determinea rotational position of the rotor of the motor 110, specifically theaxle gear 202. The rotational position of the rotor of the motor 110 maybe represented as a pulse signal generated by the speed sensor 118. Thepulse signal may be an asynchronous electrical waveform. The speedsensor 118 may be configured to oscillate, such as be displaced duringthe defect due to suspension compliance. For example, when a wheeldefect is present the speed sensor 118 may be displaced and/or oscillatewhen the wheel defect is traversed by the vehicle 100. In anotherexample, when a bearing and/or gear defect is present the speed sensor118 may be displaced and/or oscillate when the bearing and/or geardefect is traversed by the motor 110.

Returning to FIG. 1, the vehicle 100 includes the controller circuit112. The controller circuit 112 of the vehicle 100 communicates with themotors 110 to control power, tractive effort, and/or speed at which thevehicle 100 moves along the route 102. The controller circuit 112 isoperably and/or conductively coupled to the speed sensors 118. Forexample, the controller circuit 112 is configured to receive a pulsesignal generated by the speed sensors 118. The controller circuit 112includes or represents one or more hardware circuits or circuitry thatincludes and/or is connected with one or more processors,microcontrollers, or other electronic logic-based devices that performoperations described herein. The controller circuit 112 can include orbe connected with one or more operator input devices, such as levers,pedals, switches, touchscreens, or the like, to receive input from anonboard operator that controls a movement of the vehicle 100.Optionally, the controller circuit 112 can automatically control amovement of the vehicle 100, such as according to a trip plan thatdictates operational settings of the vehicle 100 (e.g., speeds, throttlepositions, brake settings, power output, or the like). In one aspect,the controller circuit 112 can control the movement of the vehicle 100according to signals received from an off-board location via acommunication system 114. For example, the communication system 114 mayreceive communication signals through one or more wired and/or wirelessconnections, where the signals dictate operational settings of thevehicle 100.

The communication system 114 includes transceiver hardware and/orcircuitry that can communicate signals with one or more othercommunication devices. The communication system 114 can include anantenna that wirelessly communicates (e.g., transmits, broadcasts,and/or receives) signals and/or the communication system 114 can becoupled with one or more conductive pathways (e.g., cables, catenaries,rails, or the like) to communicate signals through the conductivepathways.

The vehicle 110 includes a memory 116. The memory 116 includesalgorithms, data values, and/or the like utilized by the controllercircuit 112 to perform one or more operations described herein. Thememory 116 may be a tangible and non-transitory computer readable mediumsuch as flash memory, RAM, ROM, EEPROM, and/or the like.

The controller circuit 112 is operably coupled to the speed sensor 118.The controller circuit 112 is configured to determine a defect based onthe pulse signal received from the speed sensor 118. In connection withFIG. 3, the controller circuit 112 is configured to determine a wheeldefect, a bearing defect, a gear defect, and/or the like based on thepulse signal.

FIG. 3 illustrate is a flowchart of an embodiment of a method 300 formonitoring an axle drive train. The method 200, for example, may employstructures or aspects of various embodiments (e.g., systems and/ormethods) discussed herein. In various embodiments, certain steps (oroperations) may be omitted or added, certain steps may be combined,certain steps may be performed simultaneously, certain steps may beperformed concurrently, certain steps may be split into multiple steps,certain steps may be performed in a different order, or certain steps orseries of steps may be re-performed in an iterative fashion. In variousembodiments, portions, aspects, and/or variations of the method 300 maybe used as one or more algorithms to direct hardware to perform one ormore operations described herein. It should be noted, other methods maybe used, in accordance with embodiments herein.

It may be noted that the method 300 may be repeated concurrently and/orsimultaneously for each of the motors 110 and/or axles 108 of thevehicle 100. For example, the controller circuit 112 may be configuredto compare multiple axles 108 and/or motors 110. Optionally, thecontroller circuit 112 may be configured to reject common deviations ofthe motors 110 and/or axles 108 as potential irregularities along theroute 102, and/or other influences not related to a particular axle 108and/or motor 110. Additionally or alternatively, the controller circuit112 may identify which of the motors 110 and/or axles 108 of the vehicle100 include a defect. For example, the controller circuit 112 may beconfigured to categorize the defects (e.g., the bearings 208, 210, 212,214, the pinion gear 204, the speed sensor gear 216, the axle gear 202,rotor imbalance, pedestal liner, traction link defect, the wheel 104,and/or the like), which cause a speed deviation signature (e.g., basedon the pulse signal 402 of FIG. 4). The speed deviation signature isspatially synchronous to wheel rotation. For example, as described inconnection to the method 300, the defect may be recognized by itsmagnitude sensitivity to the motor torque level.

Beginning at 302, the controller circuit 112 may be configured toreceive a pulse signal 402 from the speed sensor 118 coupled to a motor110. FIG. 4 is a graphical illustration 400 of an embodiment of thepulse signal 402. The pulse signal 402 may represent a speed signatureof the motor 110 indicative of a rotational position of the motor 110over time. The pulse signal 402 is shown alongside a horizontal axis 404representative of time and a vertical axis 406 representative of peakscorresponding to teeth of the axle gear 202. The pulse signal 402 mayrepresent how rapidly the rotor and/or wheel 104 is rotating duringmovement of the vehicle 100 (shown in FIG. 1) along the route 102 (shownin FIG. 1) with respect to time. For example, the pulse signal 402 canrepresent the time domain of the rotational speeds of the rotor and/orwheel 104. It may be noted that the controller circuit 112 may receiveone or more additional pulse signals 402 obtained for one or more othermotors 110. Optionally, the controller circuit 112 may store one or moreof the pulse signals 402 in the memory 116.

At 304, the controller circuit 112 may be configured to calculate adelta time based on the pulse signal 402. The delta time may representan amount of time between one or more teeth of the speed sensor gear 216shown in FIG. 2C. For example, the axle gear 202 (FIG. 2A) may have 87teeth. The controller circuit 112 is configured to calculate changes intime between each of the 87 teeth of the speed sensor gear 216represents changes in peaks of the pulse signal 402. Optionally, thenumber of teeth for the change in time may be based on a velocity and/orrotor velocity. For example, as the velocity increases the controllercircuit 112, may increase a number of teeth for the change in time. Thechanges in the delta time may represent defects of the axle drive train.For example, increases in the delta time may represent a wheel defect, abearing defect, a gear defect, and/or the like. Optionally, thecontroller circuit 112 may store the delta times in the memory 116.

At 306, the controller circuit 112 may be configured to determine anincremental delta time for a plurality of spatial buckets based on thedelta time and an average delta time of the pulse signal 402. Forexample, the incremental delta time may represent the accumulation ofdelta times that are spatially distributed within an array defined bythe plurality of spatial buckets.

The spatial buckets may represent an angular position of the wheel 104.FIG. 5A is an illustration 500 of an embodiment of the wheel 104 of thevehicle 100 subdivided into spatial buckets (e.g., 501-505). It may benoted that the spatial buckets 501-505 shown in FIG. 5A is illustrative.For example, FIG. 5A illustrates more than five spatial buckets. Thespatial buckets 501-505 may represent angular slots and/or angularslices of the wheel 104. For example, the spatial buckets 501-505 maycorrespond to an angular position of the wheel 104. A number of thespatial buckets 501-505 may be based on a sample rate and/or processingspeed of the controller circuit 112. Additionally or alternatively, thenumber of the spatial buckets 501-505 may be based on a gear ratioand/or multiple of the gears of the axle drive train as well as thenumber of pulses per revolution provided by the speed sensor 118.

For example, the axle gear 202 (FIG. 2A) may have 87 gear teeth whilethe pinion gear 204 may have 16 teeth and the speed sensor 118 providesfor 192 pulses per motor revolution resulting in 522 spatial buckets ofthe wheel 104. The 522 spatial buckets around the wheel 104 provide fortwo-speed sensor pulses per spatial bucket.

Based on the number of spatial buckets, the controller circuit 112 maybe configured to partition and/or assign the incremental delta times toeach of the spatial buckets. For example, the horizontal axis 404 of thepulse signal 402 may represent a rotation of the rotor of the motor 110and/or the wheel 104. The controller circuit 112 may divide thehorizontal axis 404 and the pulse signal 402 into the correspondingspatial buckets. After a predetermined number of rotations and/orrevolutions of the wheel 104, the controller circuit 112 may beconfigured to determine an average and/or total delta time for eachspatial bucket. The average and/or total delta time may include directdefect signature detection and/or filtering or signal processing toidentify various drive train defects.

FIG. 5B is an illustration of a flowchart 506 of an embodiment todetermine an incremental delta time. For example, the pulse signalrepresented at 510 is received by the controller circuit 112. Thecontroller circuit 112 may filter 512 the pulse signal. The filter 512may represent a low pass filter configured to reject acceleration of thevehicle 100 of the pulse signal based on a set threshold such that rapidmovement caused by the defect are allowed passing through the filter512. At 514, the controller circuit 112 is configured to distribute thedelta times among the spatial buckets of the wheel 104. For example, thecontroller circuit 112 may assign an integral number of spatial bucketsor bins across a gear tooth of the motor 110. The motor speed or deltatime between angular positions relative to the wheel 104 a-d isaccumulated by the controller circuit 112 to develop and average thedelta times for the spatial buckets.

At 310, the controller circuit 112 may be configured to determine sumincremental delta times for the plurality of spatial buckets based on anumber of rotations of the wheel 104 a-d. For example, the controllercircuit 112 may be configured to add the incremental delta times for aplurality of revolutions (e.g., more than 30 revolutions, 48revolutions, and/or the like) of the rotor and/or the wheel 104 a-d foreach of the plurality of spatial buckets. The number of revolutions maybe based on a predetermined value stored in the memory 116. Inconnection with FIG. 5B, the controller circuit 112 may continuallystore sets of revolutions corresponding to the number of revolutions inthe memory 116 at a filter 512. The filter 512 may represent a low passfilter. For example, the filter 512 is configured to not allow slowervehicle acceleration values and/or signals from rapid changes inacceleration based on the wheel defect, the bearing defect, the geardefect, and/or the like based on the pulse signal. The addition of thedelta times across the plurality of revolutions may be utilized by thecontroller circuit to minimize detections of non-defects of the axledrive train. For example, defects on a surface of the route 102 mayincrease a delta time. Across a plurality of revolutions averaged at516, the effect of the delta time caused by the surface of the route 102is reduced and/or minimized with respect to the sum of the incrementaldelta times of the plurality of spatial buckets.

At 312, the controller circuit 112 may be configured to generate aspatial array 604. The spatial array 604 may be based on the pulsesignal 402. For example, the controller circuit 112 may continually addthe incremental delta time for each subsequent revolution of the rotorand/or the wheel 104 a-d to form the spatial array 604 until thepredetermined number of revolutions have been reached (at 518 shown inFIG. 5B). The controller circuit 112 logs incidents based on levels 520onto the memory 116.

FIG. 6 is a graphical illustration 600 of an embodiment of the spatialarray 604. The spatial array 604 is shown along a horizontal axis 602representing the spatial buckets. For example, the horizontal axis 602may correspond to the plurality of spatial buckets. The vertical axis603 may represent the sum of the incremental delta times across aplurality of revolutions for each spatial bucket. The vertical axis 603may represent microseconds. It may be noted amplitudes of the spatialarray 604 may be asynchronous across the plurality of spatial bucketsrepresented as noise. For example, a magnified portion 608 of thespatial array 604 illustrates variances in peaks across multiple spatialbuckets indicative of a spatially periodic speed disturbance source. Theperiodic variation within the spatial array 604 may be based on theinteraction of the gears within the motor 110 and/or the oscillation ofthe speed sensor 118.

Additionally or alternatively, the controller circuit 112 may beconfigured to filter out the “gear noise” of the spatial array 604 toform a gear filtered spatial array 802 (FIG. 8). For example, thecontroller circuit 112 may be configured to group sets of the pluralityof spatial buckets defined by a summing window 706 (FIG. 7). Thecontroller circuit 112 may be configured to sum the incremental deltatimes of the spatial buckets defined by the summing window 706. Thesumming window 706 may be based on a number of spatial bucketsrepresenting a single tooth of the gear of the axle gear 202. Forexample, a number of gear teeth are spatially synchronized to a wheelangular position. A number of spatial buckets, such as 522 over a wheelrevolution, may result in six buckets for a single axle/pinion geartooth translation. A size of the summing window 706 may be the gearratio and/or six spatial buckets indicative of a period contribution ofa single gear tooth to the spatial array 604. The period contributionmay be filtered out by the controller circuit 112 by applying a summingwindow averaging to the spatial array 604 corresponding to one or moreintegral number of gear teeth.

FIG. 7 is an illustration of a summing window 706 to form a gearfiltered spatial array 802. A portion of the spatial array 604 is shownwithin a table 702, which may be stored in the memory 116. For example,column 712 represents the plurality of spatial buckets with an adjacentcolumn 714 that contains the corresponding sum of the incremental deltatimes. The controller circuit 112 may select a portion of the spatialbuckets represented as the summing window 706, and sum of theincremental delta times within the summing window 706. The incrementaldelta times summed by the controller circuit 112 are stored in a table704. The table 704 may include a column 716 indicative of a position ofthe summing window 706 with respect the plurality of spatial buckets.The table 704 includes a column 718 representing a gear filtered spatialvalue. The table 704 is representative of the gear filtered spatialarray 802 shown in FIG. 8.

At an initial position of the summing window 706, the controller circuit112 may sum the incremental delta times of the spatial buckets 1-6 shownin the table 702. The sum of the incremental delta times calculated bythe controller circuit 112 may be stored in the table 704 in the column718. The controller circuit 112 may successively reposition the summingwindow 706 to an adjacent bucket in the direction of an arrow 710. Forexample, the controller circuit 112 may reposition the summing windowsuccessively along the spatial buckets. It may be noted that the summingwindow 706 may be repeated and/or cycled at the end of the table 702,such that the summing window 706 may include spatial buckets at opposingends of the table 702. For example, the summing window 706 may includethe spatial buckets (shown in the column 712) of 521, 522, and 1-4.

FIG. 8 is a graphical illustration 800 of an embodiment of the gearfiltered spatial array 802. The graphical illustration 800 may includethe gear filtered spatial array 802 and the spatial array 604. The gearfiltered array 802 and the spatial array 604 are shown along thehorizontal axis 602 and the vertical axis 603. It may be noted, the gearnoise of the spatial array 604 is removed relative to the gear filteredspatial array 802.

Additionally or alternatively, the controller circuit 112 may beconfigured to scale the sum of incremental delta times represented asthe spatial array 604 to a rotational speed of the wheel 104 a-d. FIG. 9is a graphical illustration 900 of an embodiment of the spatial array604, the gear filtered spatial array 802, and a revolutions per minute(RPM) spatial array 902. The controller circuit 112 may scale the sum ofincremental delta times based on the revolutions, utilizing Equation 1,to determine a change in revolutions per minute of the rotor of themotor 110. The variable del_dt may represent the sum of incrementaldelta time divided by the number of revolutions for a select spatialbucket of the spatial array 604. The variable RPM_(base) may representthe scaling factor of a speed of the motor 110. The variable dt_(base)may represent an amount of time for the pulse signal 402 to reach thecontroller circuit 112 at the motor speed. It may be noted that thecontroller circuit 112 may scale the spatial array 604 to a velocity,wheel velocity units, and/or the like.

$\begin{matrix}{{del\_ rpm} = \frac{{- {del\_ dt}} \times {RPM}_{base}}{{dt}_{base}}} & ( {{Equation}\mspace{14mu} 1} )\end{matrix}$

At 314, the controller circuit 112 may determine whether a wheel defectis present based on the spatial array 604. A localized wheel defect willcouple to motion in the drive train components of the motor 110 with avarying level. The degree of coupling depends on many factors includingvehicle speed, drivetrain torque levels, and the exact position of thecontact which the wheel defect shares with the route 102. The controllercircuit 112 may determine the wheel defect based on a morphology (e.g.,peak, slope, amplitude, and/or the like) of the spatial array 604 (FIG.6). For example, changes in the incremental time delta may correspond tothe wheel defect. The controller circuit 112 may be configured toidentify a peak 606 of the spatial array 604, which is indicative of thewheel defect. Optionally, the controller circuit 112 may compare thepeak 606 to a predetermined threshold to determine if the wheel defectis present. For example, if an amplitude of the peak 606 is greater thanthe predetermined threshold the controller circuit 112 may determine thewheel defect is present.

Optionally, the predetermined threshold may be dynamic. For example, thepredetermined threshold may be adjusted by the controller circuit 112based on a speed of the vehicle 100, torque levels of the motor 110, adirection of the vehicle 100 traversing the route and/or the like. Forexample, as the speed of the vehicle 100 and/or torque levels of themotor 110 increases the controller circuit 112 may increase a value ofthe predetermined threshold.

It may be noted that the controller circuit 112, may determine whether awheel defect is present based on the gear filtered spatial array 802and/or the RPM spatial array 1002 (FIGS. 10-12). FIGS. 10-12 aregraphical illustrations 1000, 1100, 1200 of an embodiment of revolutionsper minute (RPM) spatial array 1002. The RPM spatial array 1002 isplotted along a horizontal axis 1004 representing an angular positionwith respect to the wheel 104 a-d (e.g., degrees). The graphicalillustrations 1000, 1100, 1200 are shown with a vertical axis 1006representing a change in RPM. Similar to and/or the same as the spatialarray 604, the controller circuit 112 is configured to determine thewheel defect based on a morphology of the RPM spatial array 1002.

For example, the controller circuit 112 may be configured to identify apeak 1008 of the RPM spatial array 1002 (FIG. 10). The controllercircuit 112 may identify an amplitude 1010, for example of 5.2. Thecontroller circuit 112 may compare the amplitude 1010 to a predeterminedthreshold stored in the memory 116. For example, the predeterminedthreshold may be 3. Based on the amplitude 1010 being greater than thepredetermined threshold, the controller circuit may determine that awheel defect is present.

Additionally or alternatively, the controller circuit 112 may determinewhether a wheel defect is present based on a direction of the vehicle100 traversing along the route 102. For example, when the vehicle 100 istraversing along a turn and/or s-curve of the route 102 the wheel defectmay not be in contact with the route 102. The controller circuit 112 mayhold and/or wait to identify the defect of the wheel until the vehicle100 is no longer traversing along the turn and/or s-curve. For example,during the turn and/or s-curve, the controller circuit 112 may beconfigured to reject the pulse signal.

Optionally, the controller circuit 112 may be configured to determine aseverity of the defect based on a magnitude of the peak 1008. Forexample, the controller circuit 112 determines a magnitude differencebetween the amplitude 1010 and the predetermined threshold. Thedifference may be compared to a severity index stored in the memory 116.

In another example, the controller circuit 112 may compare apeak-to-peak of the RPM spatial array 1002 (FIG. 11). Defects (e.g.,wheel defect, bearing defect, gear defect) may affect multiple spatialbuckets. The controller circuit 112 may compare amplitudes of adjacentpeaks 1104, 1106 to identify defects. For example, deviations betweenmagnitudes of adjacent peaks 1104, 1106 may be an indication of thedefect severity. The controller circuit 112 may identify adjacent peaks1104 and 1106 based on slopes of the RPM spatial array 1002. The peaks1104 and 1106 have amplitudes 1007 and 1108, respectively. Thecontroller circuit 112 may determine a peak-to-peak amplitude 1102 basedon the peaks 1104 and 1106. The controller circuit 112 may identify adefect based on the peak-to-peak amplitude 1102. For example, changes inmagnitude between the peaks 1104 and 1106 may represent a defectseverity. The amplitude 1107 has a different magnitude relative to theamplitude 1108 forming a peak-to-peak amplitude 1102. Based on thepeak-to-peak amplitude 1102, the controller circuit 112 may determine aseverity of the defect. For example, the controller circuit 112 maycompare the peak-to-peak amplitude 1102 with a set of predeterminedthresholds, each representing a different severity of the defect. Inanother example, the controller circuit 112 may compare the peak-to-peakamplitude 1102 with a predetermined threshold. Based on a differencebetween the peak-to-peak amplitude 1102 and the predetermined threshold,the controller circuit 112 may determine the severity. For example, thegreater the difference of the peak-to-peak amplitude 1102 by thecontroller circuit 112, the controller circuit 112 may determine theseverity of the defect is large.

In another example, the controller circuit 112 may compare apeak-to-peak of the RPM spatial array 1002 within spatial windows 1202,1204. The spatial windows 1202, 1204 may represent a set range of timeand/or bandwidth of degrees of the wheel 104 a-d and/or spatial buckets.A size of the spatial windows 1202, 1204 may be based on a value storedin the memory 116. The controller circuit 112 may compare peaks withinthe spatial windows 1202, 1204 to detect a defect. For example, thecontroller circuit 112 may identify the peaks 1208 and 1210 within thespatial window 1202. The controller circuit 112 may identify apeak-to-peak amplitude 1206 based on the peaks 1208 and 1210. Thecontroller circuit 112 may determine that no defect within the spatialwindow 1202. For example, the controller circuit 112 may compare thepeak-to-peak amplitude 1206 with a predetermined threshold stored in thememory 116.

In another example, the controller circuit 112 may identify the peaks1212 and 1214 within the spatial window 1204. The controller circuit 112may identify a peak-to-peak amplitude 1208 based on the peaks 1212 and1214. The controller circuit 112 may determine a defect within thespatial window 1204. For example, the controller circuit 112 may comparethe peak-to-peak amplitude 1208 with the predetermined threshold storedin the memory 116.

Optionally, the controller circuit 112 may identify severity of thedefect based on pulse signals 402 from alternative sensors 118a-d. Thecontroller circuit 112 may compare the location of the defect identifiedrelative to the same location and/or time for the alternative wheels(e.g., 104 a-d). Based on differences between the peak-to-peak and/orpeak magnitudes of the alternative wheels, the controller circuit 112may determine a severity of the defect.

At 318, the controller circuit 112 may be configured to take a remedialaction based on the detection of the wheel defect. The remedial actionmay represent an alert indicative of the defect, such as taken inresponse to identifying a severity of the wheel defect. For example, thecontroller circuit 112 may be configured to generate one or more signalsthat are communicated to an operator of the vehicle 100 to notify theoperator of the identified defect of the wheel 104 a-d. These signalsmay be presented on an output device of the vehicle 100, such as adisplay (e.g., one or more liquid crystal displays (e.g., light emittingdiode (LED) backlight), organic light emitting diode (OLED) displays,plasma displays, CRT displays, and/or the like), speaker, and/or thelike. Additionally or alternatively, the controller circuit 112 may beconfigured to generate signals to automatically slow or stop themovement of the vehicle 100 without operator intervention. Thecontroller circuit 112 can generate the signals to be communicated bythe communication system 114 to one or more off-board locations, such asa repair facility, to notify the off-board location of the need tofurther inspect, adjust a maintenance schedule for the vehicle 100,and/or replace the wheel.

The type of remedial action that is taken may vary based on the severityof the defect based on the alert. For example, for larger severity ofdefect, the controller circuit 112 can automatically implement a moreimmediate remedial action, such as automatically slowing or stopping themovement of the vehicle without operator intervention. For smallerseverity of defect, the analysis system 116 can implement less immediateremedial actions, such as warning the operator of the damaged wheel,notifying the off-board location of a need to further inspect and/orreplace the wheel and/or parts of the drivetrain, or the like.Additionally or alternatively, the controller circuit 112 mayautomatically adjust a duration of a tractive effort of the axles 108and/or the motor 110 having the defect, a vehicle speed above a setthreshold, and/or the like based on the alert. For example, thecontroller circuit 112 may determine that the tractive effort and/orvehicle speed at above the set threshold may increase a severity of thedefect. The controller circuit 112 may be configured to reduce theduration of the tractive effort and/or vehicle speed to increase the useand/or operable lifespan of the component having the defect.

At 324, the controller circuit 112 may be configured to determine a gearspatial array 1412 (FIG. 14) based on grouping sets of the plurality ofspatial buckets defined by a summing window. The gear spatial array 1412is a gear waveform configured to indicate a uniform gear toothrepresentative of gear teeth, of for example the axle gear 202. Gears ofthe motor 110 may wear over time, such as aggravated by poor or lowlubrication level, high load and speed duty cycles, bearing wear causingmesh alignment loss, and/or the like. For example, wore, misaligned,and/or low lubricated gear mesh will suffer a loss of mesh efficiencyand an increase in audible noise and vibration within the motor 110. Thegear spatial array 1412 may represent an accumulated gear mesh of theaxle gear 202. In connection with FIG. 13, the controller circuit 112 isconfigured to determine the gear spatial array 1412 based on the spatialarray 604.

FIG. 13 is an illustration of an embodiment of accumulating incrementaldelta times into a gear spatial array 1412. The gear spatial array 1412Similar to FIG. 7, a portion of the spatial array 604 is shown in thetable 702, which may be stored in the memory 116. For example, thecolumn 712 represents the plurality of spatial buckets with an adjacentcolumn 714 that contains the corresponding sum of the incremental deltatimes. The controller circuit 112 may apportion the spatial buckets inthe column 712 corresponding to a position of the gear.

For example, the axle gear 202 may have 87 gear teeth having an axlegear to speed sensor 118 gear ratio of 1/six, which implies six-speedpulses may be available for every axle gear tooth translation. Thecontroller circuit 112 may apportion the sum incremental delta times inthe table 702 into six different gear buckets, shown in column 1310 ofthe table 1308. The controller circuit 112 may sum the incremental deltatimes into the column 1312 to form the gear spatial array 1412.

FIG. 14 is a graphical illustration 1400 of the gear spatial array 1412.The gear spatial array 1412 is shown along a horizontal axis 1401representing a gear tooth angle. The gear spatial array 1412 is shownwith a vertical axis 1402 representing changes in RPM of the motor 110.For example, the controller circuit 112 may scale the gear spatial array1412 into RPM units. The gear spatial array 1412 is configured to beindicative of the gear mesh of the axle gear 202. For example, thecontroller circuit 112 may be configured to determine peak-to-peaks 1404of the gear spatial array 1412. The peak-to-peaks 1404 relates to gearmesh vibration or unhealthy of the gear (e.g., the axle gear 202) and/orthe bearings 208, 210, 212, 214.

At 326, the controller circuit 112 may be configured to determinewhether a change in the gear spatial array 1412 between differentrevolution sets relative to a predetermined threshold. The differentrevolution sets may represent different incremental delta times acquiredat different groupings of revolutions. The controller circuit 112 maycompare gear spatial arrays 1412 acquired at the different revolutionsets. For example, the controller circuit 112 may compare thepeak-to-peaks 1404 of the gear spatial arrays 1412 acquired at differentrevolution sets. The differences between the peak-to-peaks 1404 may becompared with a predetermined threshold stored in the memory 116. Forexample, the predetermined threshold may represent a percentage and/ormagnitude of change between the peak-to-peaks 1404. When the changes inthe peak-to-peaks 1404 are greater than the predetermined threshold, thecontroller circuit 112 may be configured to determine that a gear defectand/or bearing defect is present.

Additionally or alternatively, the controller circuit 112 may beconfigured to determine defects of the bearings 208, 210, 212, 214, thepinion gear 208, the speed sensor gear 216, the axle gear 202, rotorimbalance, pedestal liner, traction link defect, and/or the like.Optionally, the bearings 208, 210, 212, 214, the pinion gear 208, thespeed sensor gear 216, the axle gear 202, rotor imbalance may bedetermined by the controller circuit 112 based on a morphology of thespatial array 604 (FIG. 6) and/or the gear spatial array 1412 (FIG. 14).

For example, the controller circuit 112 may be configured to determinethe defect corresponds and/or localized to the pinion gear 208, innerbearing (e.g., the bearings 208, 210 shown in FIG. 2B) and/or the speedsensor gear 216 based on a width of a peak in the spatial array 604. Thecontroller circuit 112 may be configured to identify a peak (e.g., thepeak 606) within the spatial array 604 along a revolution of the wheel104 and/or motor revolution. The controller circuit 112 may measure awidth of the identified peak across the spatial buckets along thehorizontal axis 602. For example, the width of the identified peak crossover a plurality of spatial buckets. The controller circuit 112 maycompare the width of the identified peak to a width threshold indicativeof a narrow angular signature. The narrow angular signature maycorrespond to less than ten spatial buckets (e.g., two, three, five,and/or the like). The controller circuit 112 may assign an integralnumber of spatial buckets across the motor rotation represented by thespatial array 604 within which the delta speed or delta time betweenangular positions is accumulated for the purposes of developing anaverage for each bucket.

In another example, the controller circuit 112 may be configured todetermine the defect corresponds to rotor imbalance based on a width ofa peak in the spatial array 604. The controller circuit 112 may beconfigured to identify a peak (e.g., the peak 606) within the spatialarray 604 along a revolution of the wheel 104 and/or motor revolution.The controller circuit 112 may measure a width of the identified peakacross the spatial buckets along the horizontal axis 602. For example,the width of the identified peak cross over a plurality of spatialbuckets. The controller circuit 112 may compare the width of theidentified peak to a width threshold indicative of a broad spatialangular signature. The broad spatial angular signature may correspond toover ten spatial buckets (e.g., fifteen, twenty, thirty, and/or thelike). The controller circuit 112 may assign an integral number ofspatial buckets across the motor rotation represented by the spatialarray 604 within which the delta speed or delta time between angularpositions is accumulated for the purposes of developing the average foreach bucket.

Optionally, the integral number of spatial bucks are spread acrossvarious roller or roller cage expected rotations which are directlyrelated to the motor speed. Additionally or alternatively, the detectionby the controller circuit 112 of a defect on the pinion gear 208, innerbearing (e.g., the bearings 208, 210), or a rotor imbalance may beconfigured to assign an integral number of spatial buckets across themotor rotation of the spatial array 604 within which variations foradditional sensors coupled to the motors 110. For example, theadditional sensors may include at least one of a motor current sensor, avoltage sensor, an accelerometer, and/or the like is accumulated for thepurposes of developing the average for the spatial buckets.

In another example, the controller circuit 112 may be configured toidentify an outer race bearing defect (e.g., the bearings 212, 214)based on a morphology of the spatial array 604 (FIG. 6) and/or the gearspatial array 1412 (FIG. 14). The controller circuit 112 may identify awidth of a peak (e.g., the peak 606) having a width across a pluralityof spatial buckets corresponding to a bearing width. The bearing widthmay represent a number of spatial buckets corresponding to an angularwidth of the wheel 104 corresponding to a rolling bearing (e.g., thebearings 212, 214) of the wheel 104 and/or motor revolution. When thewidth of the identified peak has a bearing width, the controller circuitmay be configured to determine an outer race bearing defect.

If the controller circuit 112 determines the gear change is above thethreshold, then at 328, the controller circuit 112 may take a remedialaction based on the detection of the gear defect. The remedial actionmay represent an alert indicative of the defect. For example, thecontroller circuit 112 may be configured to generate one or more signalsthat are communicated to an operator of the vehicle 100 to notify theoperator of the identified defect of the bearing and/or gear. Thesesignals may be presented on an output device of the vehicle 100, such asa display (e.g., one or more liquid crystal displays (e.g., lightemitting diode (LED) backlight), organic light emitting diode (OLED)displays, plasma displays, CRT displays, and/or the like), speaker,and/or the like. Additionally or alternatively, the controller circuit112 may be configured to generate signals to automatically slow or stopmovement of the vehicle 100 without operator intervention. Thecontroller circuit 112 can generate the signals to be communicated bythe communication system 114 to one or more off-board locations, such asa repair facility, to notify the off-board location of the need tofurther inspect, adjust a maintenance schedule for the vehicle 100,and/or replace the bearing and/or gear.

The type of remedial action that is taken may vary based on the severityof the defect and the alert. For example, the controller circuit 112 maydetermine that magnitude of the differences between the peak-to-peaks1412 relative to the predetermined threshold is indicated of theseverity of the defect of the bearing and/or gear. For larger severityof defect, the controller circuit 112 can implement a more immediateremedial action, such as automatically slowing or stopping the movementof the vehicle without operator intervention. For smaller severity ofdefect, the analysis system 116 can implement less immediate remedialactions, such as warning the operator of the damaged bearing and/orgear, notifying the off-board location of a need to further inspectand/or replace the bearing or gear, and/or the like. Additionally oralternatively, the controller circuit 112 may automatically adjust aduration of a tractive effort of the axles 108 and/or the motor 110having the defect, a vehicle speed above a set threshold, and/or thelike based on the alert. For example, the controller circuit 112 maydetermine that the tractive effort and/or vehicle speed at above the setthreshold may increase a severity of the defect. The controller circuit112 may be configured to reduce the duration of the tractive effortand/or vehicle speed to increase the use and/or operable lifespan of thecomponent having the defect.

In an embodiment a system (e.g., monitoring system) is provided. Thesystem includes a speed sensor coupled to a traction motor of an axledrive train of a vehicle. The speed sensor is configured generate apulse signal indicative of a rotational position of the traction motor.The system includes a controller circuit operatively coupled to thespeed sensor. The controller circuit is configured to analyze the pulsesignal to identify per-revolution signal reoccurrences that meetdesignated criteria, and to determine the defect based on theper-revolution signal reoccurrences that are identified. The defect isone or more of a wheel defect, a bearing defect, or a gear defect.

Optionally, the controller circuit is configured to calculate a deltatime or delta speed for a plurality of spatial buckets based on thepulse signal, and determine an incremental delta time or delta speed forthe plurality of spatial buckets based on the delta time and an averagedelta time or delta speed of the pulse signal. The controller circuit isconfigured to use the incremental delta time or delta speed to determinethe defect. Additionally or alternatively, the controller circuit isconfigured to determine a sum incremental delta time or delta speed forthe plurality of spatial buckets based on a number of rotations of awheel. Additionally or alternatively, the controller circuit isconfigured to determine a gear filtered spatial array based on groupingsets of the plurality of spatial buckets defined by a summing window.Additionally or alternatively, the controller circuit is configured toscale the sum incremental delta time to a rotational speed of the wheelor the traction motor. Additionally or alternatively, the controllercircuit is configured to remove or filter out gear meshing variation byspatially averaging the signals over an integral number of gear teeth.

Optionally, the controller circuit is configured to generate a spatialarray based on the pulse signal, and to determine the defect based on amorphology of the spatial array. Additionally or alternatively, thecontroller circuit is configured to determine a severity of the defectbased on a magnitude of the peak.

Optionally, the controller circuit is configured to generate an alertindicative of the defect. Additionally or alternatively, the controllercircuit is configured to automatically adjust at least one of the speedof a vehicle, alert an operator of the vehicle, or a maintenanceschedule of the vehicle responsive to determining the defect based onthe alert. Additionally or alternatively, the controller circuit isconfigured to automatically adjust a tractive effort duration of an axlehaving the defect or a vehicle speed based on the alert.

In an embodiment a method (e.g., for monitoring an axle drive train) isprovided. The method includes receiving a pulse signal from a speedsensor coupled to a traction motor. The pulse signal is indicative of arotational position of the traction motor. The method includes analyzingthe pulse signal to identify per-revolution signal reoccurrences thatmeet designated criteria, and determining a defect based on theper-revolution signal reoccurrences that are identified. The defect isone or more of a wheel defect, a bearing defect, or a gear defect.

Optionally, the method includes calculating a delta time for a pluralityof spatial buckets based on the pulse signal, and determining anincremental delta time for the plurality of spatial buckets based on thedelta time and an average delta time of the pulse signal. Theincremental delta time is used to determine the defect. Additionally oralternatively, the method includes determining a sum incremental deltatime for the plurality of spatial buckets based on a number of rotationsof a wheel. Additionally or alternatively, the method includesdetermining a gear filtered spatial array based on grouping sets of theplurality of spatial buckets defined by a summing window. Additionallyor alternatively, the method includes filtering out gear meshingvariation by spatially averaging the signals over an integral number ofgear teeth. Additionally or alternatively, the method includes scalingthe sum incremental delta time to a rotational speed of the wheel.

Optionally, the method includes generating a spatial array based on thepulse signal, and determining a defect based on a morphology of thespatial array. Additionally or alternatively, the method includesdetermining a severity of the defect based on a magnitude of the peak.

Optionally, the method includes generating an alert indicative of thedefect. Additionally or alternatively, the method includes automaticallyadjusting at least one of a speed of a vehicle, alert an operator of thevehicle, or a maintenance schedule of the vehicle based on the alert.

In an embodiment a system (e.g., monitoring system) is provided. Thesystem includes a controller circuit configured to receive a signal froma speed sensor of a vehicle. The signal representative of rotationalpositions of a motor of the vehicle. The controller circuit isconfigured to analyze the signal to identify per-revolution signalreoccurrences that meet designated criteria, and to determine the defectbased on the per-revolution signal reoccurrences that are identified inone or more of a wheel of the vehicle, a bearing of the vehicle, or agear of the vehicle based on the signal.

Optionally, the controller circuit is configured to automatically reducea speed of the vehicle responsive to determining the defect.

Multiple instances of “one or more processors” does not mean the systemsare embodied in different processors, although that is a possibility.Instead, the one or more processors of the systems described herein maybe the same as the one or more processors of the same or differentsystem, such that in one embodiment, different systems can be embodiedin the same processor or the same multiple processors.

Components of the systems described herein may include or representhardware circuits or circuitry that include and/or are connected withone or more processors, such as one or more computer microprocessors.The operations of the methods described herein and the systems can besufficiently complex such that the operations cannot be mentallyperformed by an average human being or a person of ordinary skill in theart within a commercially reasonable time period. For example, thegeneration and/or analysis of the speed signatures may take into accounta large amount of factors, may rely on relatively complex computations,and the like, such that such a person cannot complete the analysis ofthe speed signatures within a commercially reasonable time period.

As used herein, a structure, limitation, or element that is “configuredto” perform a task or operation is particularly structurally formed,constructed, programmed, or adapted in a manner corresponding to thetask or operation. For purposes of clarity and the avoidance of doubt,an object that is merely capable of being modified to perform the taskor operation is not “configured to” perform the task or operation asused herein. Instead, the use of “configured to” as used herein denotesstructural adaptations or characteristics, programming of the structureor element to perform the corresponding task or operation in a mannerthat is different from an “off-the-shelf” structure or element that isnot programmed to perform the task or operation, and/or denotesstructural requirements of any structure, limitation, or element that isdescribed as being “configured to” perform the task or operation.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the inventivesubject matter without departing from its scope. While the dimensionsand types of materials described herein are intended to define theparameters of the inventive subject matter, they are by no meanslimiting and are exemplary embodiments. Many other embodiments will beapparent to one of ordinary skill in the art upon reviewing the abovedescription. The scope of the inventive subject matter should,therefore, be determined with reference to the appended claims, alongwith the full scope of equivalents to which such claims are entitled. Inthe appended claims, the terms “including” and “in which” are used asthe plain-English equivalents of the respective terms “comprising” and“wherein.” Moreover, in the following claims, the terms “first,”“second,” and “third,” etc. are used merely as labels, and are notintended to impose numerical requirements on their objects. Further, thelimitations of the following claims are not written inmeans-plus-function format and are not intended to be interpreted basedon 35 U.S.C. § 112(f), unless and until such claim limitations expresslyuse the phrase “means for” followed by a statement of function void offurther structure.

This written description uses examples to disclose several embodimentsof the inventive subject matter and also to enable one of ordinary skillin the art to practice the embodiments of inventive subject matter,including making and using any devices or systems and performing anyincorporated methods. The patentable scope of the inventive subjectmatter is defined by the claims, and may include other examples thatoccur to one of ordinary skill in the art. Such other examples areintended to be within the scope of the claims if they have structuralelements that do not differ from the literal language of the claims, orif they include equivalent structural elements with insubstantialdifferences from the literal languages of the claims.

The foregoing description of certain embodiments of the presentinventive subject matter will be better understood when read inconjunction with the appended drawings. To the extent that the figuresillustrate diagrams of the functional blocks of various embodiments, thefunctional blocks are not necessarily indicative of the division betweenhardware circuitry. Thus, for example, one or more of the functionalblocks (for example, processors or memories) may be implemented in asingle or multiple pieces of hardware (for example, electronic circuitsand/or circuitry that include and/or are connected with one or moreprocessors, microcontrollers, random access memories, hard disks, andthe like). Similarly, the programs may be stand-alone programs, may beincorporated as subroutines in an operating system, may be functions inan installed software package, and the like. The various embodiments arenot limited to the arrangements and instrumentality shown in thedrawings.

As used herein, an element or step recited in the singular and proceededwith the word “a” or “an” should be understood as not excluding pluralof said elements or steps, unless such exclusion is explicitly stated.Furthermore, references to “one embodiment” of the present inventivesubject matter are not intended to be interpreted as excluding theexistence of additional embodiments that also incorporate the recitedfeatures. Moreover, unless explicitly stated to the contrary,embodiments “comprising,” “including,” or “having” an element or aplurality of elements having a particular property may includeadditional such elements not having that property.

What is claimed is:
 1. A system comprising: a speed sensor coupled to atraction motor of an axle drive train of a vehicle, wherein the speedsensor is configured to generate a pulse signal indicative of arotational position of the traction motor; and a controller circuitoperatively coupled to the speed sensor, the controller circuitconfigured analyze the pulse signal to identify per-revolution signalreoccurrences that meet designated criteria, and to determine a defectbased on the per-revolution signal reoccurrences that are identified,wherein the defect is one or more of a wheel defect, a bearing defect,or a gear defect.
 2. The system of claim of claim 1, wherein thecontroller circuit is configured to calculate a delta time or deltaspeed for a plurality of spatial buckets based on the pulse signal, anddetermine an incremental delta time or delta speed for the plurality ofspatial buckets based on the delta time and an average delta time ordelta speed of the pulse signal, wherein the controller circuit isconfigured to use the incremental delta time or delta speed to determinethe defect.
 3. The system of claim 2, wherein the controller circuit isconfigured to determine a sum incremental delta time or delta speed forthe plurality of spatial buckets based on a number of rotations of awheel.
 4. The system of claim 3, wherein the controller circuit isconfigured to determine a gear filtered spatial array based on groupingsets of the plurality of spatial buckets defined by a summing window. 5.The system of claim 3, wherein the controller circuit is configured toscale the sum incremental delta time to a rotational speed of the wheelor the traction motor, and the controller circuit is configured toremove or filter out gear meshing variation by spatially averaging thesignals over an integral number of gear teeth.
 6. The system of claim 1,wherein the controller circuit is configured to generate a spatial arraybased on the pulse signal, and to determine the defect based on amorphology of the spatial array, and the controller circuit isconfigured to determine a severity of the defect based on a magnitude ofa peak.
 7. The system of claim 1, wherein the controller circuit isconfigured to generate an alert indicative of the defect.
 8. The systemof claim 1, wherein the controller circuit is configured toautomatically adjust at least one of the speed of a vehicle, alert anoperator of the vehicle, or adjust a maintenance schedule of the vehicleresponsive to determining the defect.
 9. The system of claim 8, whereinthe controller circuit is configured to automatically adjust a tractiveeffort duration of an axle having the defect or a vehicle speedresponsive to determining the defect.
 10. A method comprising: receivinga pulse signal from a speed sensor coupled to a traction motor, whereinthe pulse signal is indicative of a rotational position of the tractionmotor; analyzing the pulse signal to identify per-revolution signalreoccurrences that meet designated criteria; and determining a defectbased on the per-revolution signal reoccurrences that are identified,wherein the defect is one or more of a wheel defect, a bearing defect,or a gear defect.
 11. The method of claim 10, further comprisingcalculating a delta time for a plurality of spatial buckets based on thepulse signal.
 12. The method of claim 10, further comprising determininga sum incremental delta time for the plurality of spatial buckets basedon the delta time and an average delta time of the pulse signal, whereinthe incremental delta time is used to determine the defect.
 13. Themethod of claim 12, wherein the sum incremental delta time for theplurality of spatial buckets is further determined based on a number ofrotations of a wheel.
 14. The method of claim 13, further comprisingdetermining a gear filtered spatial array based on grouping sets of theplurality of spatial buckets defined by a summing window.
 15. The methodof claim 13, further comprising filtering out gear meshing variation byspatially averaging the signals over an integral number of gear teeth.16. The method of claim 15, further comprising scaling the sumincremental delta time to a rotational speed of the wheel.
 17. Themethod of claim 10, further comprising generating a spatial array basedon the pulse signal, determining the defect based on a morphology of thespatial array, and determining a severity of the defect based on amagnitude of a peak, and generating an alert indicative of the defect.18. The method of claim 10, further comprising automatically adjustingat least one of a speed of a vehicle, alerting an operator of thevehicle, or adjusting a maintenance schedule of the vehicle responsiveto determining the defect.
 19. A system comprising: a controller circuitconfigured to receive a signal from a speed sensor of a vehicle, thesignal representative of rotational positions of a motor of the vehicle,wherein the controller circuit is configured to analyze the signal toidentify per-revolution signal reoccurrences that meet designatedcriteria, and to determine a defect based on the per-revolution signalreoccurrences that are identified in one or more of a wheel of thevehicle, a bearing of the vehicle, or a gear of the vehicle based on thesignal.
 20. The system of claim 19, wherein the controller circuit isconfigured to automatically reduce a speed of the vehicle responsive todetermining the defect.